Knob



FIG. 1 is a perspective view of a knob showing our new design;

FIG. 2 is a left side view thereof, the right side view being a mirror image of the left side view shown;

FIG. 3 is a front view thereof; and,

FIG. 4 is a rear view thereof.

The broken line illustration of the mounting aperture in FIG. 4 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a knob, as shown and described. 